Electro-copolymerisation of indene and styrene

Electroinitiated cationic copolymerisation of indene and styrene was investigated by constant potential electrolysis. Effects of copolymerisation potential and temperature on the copolymer composition and the reactivity ratios are discussed. The reactivity ratios of the monomers were calculated according to the integrated Lewis-Mayo equation.     

Research on Poly （Styrene-Crylicacid）-Suported Neodymium Complex Catalytic Copolymerization of Styrene and 4-Vinylpyridine

Research on Poly(Styrene-Crylicacid)-Suported Neodymium Complex Catalytic Copolymerization of Styrene and 4-Vinylpyridine     

苯乙烯焦油综合利用的研究进展

苯乙烯焦油为苯乙烯生产过程中产生的副产品,其主要成分是苯乙烯聚合物以及组成复杂的衍生物、低聚物等,一般作为燃料燃烧或废物出厂.随着环保管控的升级,苯乙烯焦油的加工利用难度也随之增大.近年来,为解决苯乙烯焦油的有效利用问题,以提高其利用价值,对其进行了研究,主要包括炼油装置掺炼,回收有效组分,制备磺酸盐,用于石油开采等方...     

Updated evaluation of the migration of styrene monomer and oligomers from polystyrene food contact materials to foods and food simulants

Due to the 2011 labelling of styrene monomer as “reasonably anticipated to be a human carcinogen” by the National Institutes of Health’s National Toxicology Program (NTP) and the controversy over whether styrene oligomers mimic the physiological effects of estrogen, an updated review of styrene monomer and oligomers in food and food contact materials (FCMs) was performed. The concentrations of styrene monomer and oligomers were determined in 24 polystyrene (PS) products and ranged from 9.3 to 3100 mg kg^–1 for the styrene monomer, 130–2900 mg kg^–1 for the sum of three styrene dimers, and 220–16,000 mg kg^–1 for the sum of six styrene trimers. Foods in contact with PS packaging had styrene monomer concentrations ranging from 2.6 to 163 ng g^–1; dimer concentrations from the limit of quantitation (LOQ) to 4.8 ng g^–1 and trimer concentrations were all below the LOQ (2 ng g^–1). Diffusion coefficients (D_p) and partition coefficients (K) were also calculated for styrene dimers and trimers. The results presented here indicate that styrene monomer concentrations in foods have not significantly changed since the 1980s and monomer concentrations in food packaging quantified in this study were all below USFDA limits. Although styrene dimers and trimers are present in higher concentrations in PS FCMs than the monomer, their migration to food is limited because of their high K values (4 × 10² to 2 × 10⁶) and their low diffusion coefficients in PS products. Additionally, diffusion coefficients calculated using USFDA-recommended food simulants and Arrhenius plots describing the temperature dependence of styrene dimers and trimers can be used in future calculations of dietary intake of the styrene oligomers.     

丙烯酸树脂类纸张透明剂对纸张性质的影响

以丙烯酸甲酯、丙烯酸丁酯和苯乙烯为原料,采用乳液聚合法,合成丙烯酸酯类纸张透明剂;并用所得透明剂浸渍纸张,探讨其对纸张透明度、白度、透气度、抗张指数、耐折度和耐破指数的影响。     

SMA在麦草浆AKD施胶纸上的应用

用自制的苯乙烯．马来酸酐共聚物盐(SMA)对经过AKD施胶的漂白麦草抄造的纸进行了表面施胶实验,实验发现：SMA分子质量高,纸的施胶度增大,透气度值下降,相对分子质量超30000时,纸的施胶度不再有明显的提高,而透气度值则继续降低;钠盐的抗水性较差,但对纸页的成膜能力较强．且明显好于SMA铵盐;苯乙烯对马来酸酐比例越大,赋予纸页表面的抗水性和平滑度越好。与SMA共同进行表面施胶的阴离子淀粉对纸页平滑度和IGT拉毛强度的改善明显好于氧化淀粉;木薯淀粉表面施胶性能优于玉米淀粉。     

Taste recognition threshold concentrations of styrene in oil-in-water emulsions and yoghurts

Taste recognition threshold concentrations (TRTC) of styrene were determined in samples of oil-in-water emulsions (30–300 g kg^?1 oil) and yoghurts (1–30 g kg^?1 fat), spiked with styrene. The observed TRTC increased linearly with increasing fat content and ranged from 0–3 to 2–1 mg kg^?1 for the emulsions and from 36 to 171 g kg^?1 for the yoghurts. Styrene equilibrium partition coefficients between emulsions and their respective vapour phases were determined. The concentrations of styrene in the continuous aqueous phase of the emulsions and yoghurts were calculated at the TRTC. The styrene concentrations in the continuous phase had constant values of about 15 g kg^?1 indicating that perception of styrene for oil-in–water emulsions is determined by the aqueous phase of the emulsion. The concentrations of styrene in the vapor phases above the emulsions and yoghurts were also calculated and were found to be constant at the TRTC. This relationship probably resulted from the equilibrium of distribution of styrene between the respective phases. Commercial yoghurt packed in polystyrene beakers contained styrene levels in the range 2–11 g kg^?1, much lower then the TRTC reported.     

苯乙烯共聚物在造纸工业中的应用

苯乙烯共聚物在造纸工业作为湿部添加剂如中性施胶剂、增干强剂、助留助滤剂及加工纸用化学品等,已经引起人们的重视并得到了广泛的应用.文章介绍了苯乙烯共聚物在造纸工业中的应用现状.     

热裂解-GC/MS评估烟草苯系物产生量的影响因素

本研究以带有吸附阱的热裂解装置作为裂解反应器,采用高温裂解、低温吸附后热脱附并结合GC/MS在线检测的方法,测定了空气氛围中不同裂解条件下烤烟裂解产生的苯系物(包括苯、甲苯、对二甲苯、苯乙烯、邻/间二甲苯).实验中考察了裂解条件的变化对裂解产物中苯系物产生量的影响,考察的因素包括:裂解终温(600℃、700℃、800℃...     

PAE／苯乙烯接枝共聚物乳液在不同纸浆中的应用

以聚酰胺多胺环氧氯丙烷（PAE）、苯乙烯为主要原料,在过硫酸铵-亚硫酸氢钠氧化还原引发体系下合成PAE／苯乙烯接枝共聚物乳液,并通过红外光谱对其结构进行了表征。通过在不同纸浆中应用分析发现,PAE／苯乙烯接枝共聚物乳液对纸张有较好的增强作用,在瓦楞纸浆中应用时乳液加入量以1．0％质量分数（对绝干浆）为宜,在木浆中应用时乳液加入量应以0．8％质量分数（对绝干浆）为宜。